We turn to that grilling on capitol hill for Dr. Oz. He is one of America's most famous and trusted doctors but he was under fire from members of congress for making claims on his TV show about miracle weight loss. ABC's David Kerley covered the hearing in Washington. Good morning, David. Reporter: Good morning, George. Dr. Oz says he came here to crack down on scam marketers of diet products but it was Dr. Oz who got some of the toughest questions. Welcome to a new season. Reporter: America's trusted TV doctor -- Miracle pill can burn fat fast. Reporter: Found himself in the hearing room hot seat Tuesday. I can't figure this out, Dr. Oz. I don't get why you need to say this stuff because you know it's not true. I would give my audience the advice I give my family all the time. Reporter: Senators are worried about diet scams, billions of dollars worth and even some of the language that Dr. Oz uses when talking about products. When you call a product a miracle and it's something you can buy and it's something that gives people false hope, I just don't understand why you need to go there. My job, I feel, on the show is to be a cheerleader for the audience and when they don't think they have hope, when they don't think they can make it happen I want to look everywhere including alternative healing traditions for any evidence supportive to them. Taking green coffee extract doubles your weight loss. Reporter: Just weeks after that statement websites started popping up selling it. One Florida company even using Dr. Oz's show on its website. A site which according to a federal lawsuit against the company includes false advertising and paid testimonials and attorney for that company calls the charges misleading and baseless. Dr. Oz says he doesn't give his company permission to use his show or his name. I use language that was very passionate but ended up not being helpful but incendiary and it provided fodder for unscrupulous advertisers. Reporter: But after the hearing the TV doctor did tell us he has made some mistakes. Sounds to me like you'll be more care careful. I'll be more careful and it hasn't made a dent in this problem and that's what concerns me. He told me he met with officials from the federal trade commission and plans to work with that agency as he said to drain the swamp of unscrupulous marketers of diet products. George? Yeah. I can so relate to that. On my Twitter account, people will send a little -- a tweet saying, robin, thank you for sharing your weight loss with you. I didn't do it. They link it to something I have nothing to -- You never gave permission. I have nothing to do with it and I keep blocking them. They keep doing it and keep telling my people who follow me this is not me but are able to somehow do this. It's aggravating. We'll move on to that teen

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